Oil burner



Sept. 13, 1955 w. B. PERDUE OIL BURNER Filed Sept. 14, 1949 5Sheets-Sheet 2 INVENTOR. Zflz'lliczm B. Jewdue BY W85 Sept. 13, 1955 w.B. PERDUE 2,717,633

OIL BURNER Filed Sept. 14, 1949 5 Sheets-Sheet 5 IN V EN TOR.

Zfl jlliczm B Pemiae Sept. 13, 1955 w. B. PERDUE 2,717,638

OIL BURNER Filed Sept. 14, 1949 5 Sheets-Sheet 4 INVENTOR. Zfl jllia/n2?. J e/"due Sept. 13, 1955 w. B. PERDUE 2,717,638

011. BURNER Filed Sept. 14, 1949 5 Sheets-Sheet 5 5/ INVENTOR.

M'ZZZQ/n B Pemiwe United States Patent 0 OIL BURNER William B. Perdue,Waukegan, Ill.

Application September 14, 1949, Serial No. 115,665

8 Claims. (Cl. 158-76) This invention relates to an oil burner and morespecifically to the complete apparatus for the combustion air supplysystem employed, and to the various means and mechanisms used to producea quiet and efiicient burner having a hot clear flame with comparativelylow fuel consumption with a correspondingly economical operation.

The design and construction of oil burners have always presentednumerous problems of variable natures with no actual classification asto their individual importance in the oil burner structures. Burnernozzles, heads, cones, air supply means and oil supply means togetherwith fiow controls, etc., cannot be considered individually in a burnersystem to obtain the optimum in design and construction for theincreased efficiency of a unit paralleled by noticeable savings inoperating costs and maintenance.

It is one of the main objects of the present invention to provide acompletely correlated combination of structures to increase the maximumefiiciency of an oil burner by a controlled air supply system for afixed oil supply ratio to eliminate variable output under the sameconditions of use. The air supplied by this burner is only needed airfor combustion, no more, no less, and the manner of commingling of theair with the oil is also an improved departure from the conventional oilburner tactics of the past and present day methods. In burners as atpresent or previously produced the volume and/ or static pressure of thecombustion air have been given little attention. Consequently correctfan housing designs have not been employed. Fan housing designs havelong been known, but such housings as described herein, have never beenused in combination with the features herein embodied in an oil burner,wherein the incorporation of such a housing functioning as described isessentially new.

The present invention also contemplates certain adjustments of thesystem by the composite mechanisms contributing to the value of theburner. For example, the head and cone are relatively movable at theexhaust end of the blast tube for controlling the volume and/ or the airpressure at the outlet end of the blast tube. Air inlet adjusting meansare also used in obtaining a final adjustment after a balanced systemhaving a predetermined static pressure in the blast tube has beenestablished by the amount of opening selectively provided between thehead and cone of the oil burner. This is a new and necessary feature inthe present burner design for obtaining the results contemplated in thisunit.

As a further improvement, the burner is constructed for resilient andnoiseless support from the wall of the heater, boiler or furnace, thusgiving quiet operation with a minimum of vibration to eliminatedisturbances such as would directly affect shifting or loosening of theadjustable burner mechanisms and to thereby insure constant highlyefliciency B. t. u. output under the exact conditions and adjustmentsselected for the operation of a particular burner.

"ice It is another object of this oil burner to use for the first time afan and housing or blower with a housing of a prescribed design andperformance in combination with a burner blast tube, which housing willhave a fixed and tested air output during operation to supply the blasttube with a constant air delivery to create in said tube, in combinationwith the burner head and air cone control at the outlet end of saidtube, a predetermined plenum of air under a given static air pressure.This involves the use of a housing scroll of optimum design with theproper cut-off correctly rounded and spaced in proper relation to theblower wheel and housing inlet. And as one of the main controllingconsiderations, this static air delivery feature of the fan housing mustinclude the proper size air inlet to the fan or blower wheel.

Through experience it has been found that the fan intake area must havean uninterrupted area of approach which is equal in area to one andone-half times the area of the fan inlet to establish and maintain aconstant static air pressure in the burner blast tube.

The oil burner of the present invention includes a blower having theabove characteristics with a housing of integrally cast walls to formthe required inlet and outlet chambers to connect with the burner blasttube for functioning in the manner described.

The oil burner of this invention includes such features as providing anintegral fan housing design to eliminate recirculation of inlet air; toprovide means for testing the static pressure of the blast tube air; toprovide an air cone design incorporated into this burner to obtain acombustible mixture with high economy fuel consumption; and amongstothers, to incorporate an arrangement of nozzle and oil line toeliminate soot and stench by automatically guarding against after dripof the fuel oil.

Other features and advantages embodied into the present design of oilburner shall hereinafter appear in the following detailed descriptionhaving reference to the accompanying drawings all forming a part of thisspecification.

In the drawings:

Fig. 1 is a side elevational view of an oil burner constructed accordingto the principles above set forth I to carry out the improved functionsstated, this illustration showing a general installation of the oilburner for a heater;

Fig. 2 is a fragmentary detail cross sectional view of the upper burnersupport as attached to the top of the oil burner;

Fig. 3 is another fragmentary detail cross sectional view of the lowerburner support as the same is attached to the bottom of the oil burner;

' Fig. 4 is an end elevational view of the oil burner as seen from theblast tube end thereof to show the supporting bracket as if removed fromthe burner with the securing screws shown in section;

Fig. 5 is a vertical cross sectional view of the bracket and adjacentburner parts substantially as seen along the plane of the line 5--5 inFig. 4;

Fig. 6 is a transverse vertical cross sectional view through the burnerfan housing and associated airchambers as seen substantially along theplane of the line 66 in Fig. l and illustrating the means that preventsair recirculation;

Fig. 7 is another vertical cross sectional View of the burner fanhousing as taken along the line 77 in Fig. 6 with the fan and drivemeans omitted to better illustrate certain details of construction;

Fig. 8 is a fragmentary transverse vertical cross sectional view of thefan housing of another form of oil burner to show a further contemplatedstructure for preventing air recirculation.

Fig. 9 is a face view of the air deflector ring used in the Fig. 8 oilburner;

Fig. 10 is a perspective view of a fragmentary portion of the dischargeend of the blast tube with the latter partially broken away and insection to show the head and cone as Well as their relationship, partsof the head and cone also being broken away and in section to show someof the salient features of their design;

Fig. ll is a face view of the cone as seen from the side disposed withinthe blast tube but with the cone removed from the tube to show thesurface contour of the structure and design of the cone for directingthe air in front of the oil nozzle and into the oil mist zone beyond theburner head;

Fig. 12 is a side elevational view of the air cone per se to show otherof the details thereof;

Fig. 13 is a vertical longitudinal cross sectional view of the dischargeend of the blast tube to show the air cone and the head as they wouldappear when viewed substantially along the line 13-13 in Fig. 10;

Fig. 14 is an end view of the burner head per se as it appears whenviewed from the oil nozzle end thereof; and

' Fig. 15 is a side elevational view of the oil burner as seen from thereverse side of Fig. 1 to show the oil supply system and the connectionsthereof leading to the head of the oil burner.

The oil burner as best seen in Fig. 1 comprises an integrally cast fanhousing 1 carrying a motor 2 and an ignition transformer 3, and saidhousing 1 being rigidly joined with a blast tube 4 adapted forcommunication with a combustion chamber such as 5 disposed within aheater or boiler 6. Fig. 15 shows the reverse side of the burner and theconnected fuel oil pump 7 having an oil line 8 connected with an oilline 9 through a coupling 10 passing into an elongated clearance opening10a. Fuel oil is supplied through an oil line 11 from a suitablereservoir and the oil is directed to the oil burner head 12 through theoil line 9.

To provide a quiet running unit of minimum vibration coupled with thefacility of securing the same directly to the wall of the heater orboiler, the burner structure is coupled with a cast bracket 13illustrated in Figs. 1 to 5. This arrangement permits the oil burner tobe rigidly supported upon the device for which it provides heat and thisform of a support eliminates floor standards, pedestals, together withcement blocks and adjustable means normally used for mounting an oilburner adjacent a heating unit.

Bracket 13 is of light weight construction comprising an annular body 14with an upstanding arm 15 and a depending apron 16 each disposed atopposite edges of the body 14 and in vertical alignment, said members14, 15 and 16 including appropriately arranged bolt holes 17 for bolts18 which securely fasten the bracket to the wall 19 of the heater 6. Thebody 14 has an opening 20 for the blast tube 4, the opening beingoutlined by a pcripheral flange 21. Flange 21 is large enough tocompactly encircle an asbestos fabric wrapping 22 which is wound aboutthe tubular exhaust sleeve 23 that comprises part of the fan housing 1.

Sleeve 23 which forms an integral part of housing 1 is shouldered at 24and snugly receives the housing end of the blast tube 4 fixing the tubeto the sleeve by such means as the screws 25 as shown in Figs. 4 and 5thus providing a snug air tight seal between the blast tube 4 and thehousing 1. Several annular grooves 26 are positioned to surround theblast tube opening 20 in bracket 13 and packing 27 may be used ingrooves 26 for the purpose of contacting the wall 19 of the heater toproduce an air tight seal at the heater opening 28 as seen in Figs. 1and 5. The outer or discharge end of the blast tube 4 is received in anopening 29 in the wall 30 of the combustion chamber 5, and a winding ofashestos fabric 31 surrounds tube 4 and is interposed between the tube 4and the circular wall of opening 29 to further quiet noise andoperational vibrations. This asbestos fabric 31 and the manner ofreceiving the end of the tube 4 in the combustion chamber wall opening29 lends further rigidity to the burner and acts to stabilize thesupported burner and its parts.

The mounting of the burner as a self contained and bodily attachableunit to the wall 19 of the heater 6 is completed through upper and lowerbracket supported mountings 32 and 33 respectively as illustrated inFigs. 1 to 5 inclusive. The upper mounting 32 comprises a tube 34 fixedin the upper bracket boss 35 to project outwardly over the fan housing 1to be encircled by a two part clamp 36 that is tightened by nut and boltmeans 37 and 38 which also simultaneously secure the clamp structure tothe top of the fan housing 1 as seen in Fig. 2. A rubber sleeve 39 isinterposed between the tube 34 and the tube encircling clamp parts 36aand 36b for dampening vibrations and noises to counteract thetransmittal of noises to the heater 6 through the bracket 13 with thecorresponding resilient supporting action of the oil burner to limitvibratory disturbance in the latter which may throw burner parts out ofadjustment caus ing improper functioning of the burner.

The lower mounting 33 comprises a vertical tube 40 having a threadedhead 41 to screw into the internally threaded boss 42 forming a part ofthe fan housing 1, and including a clamp 43 having parts 43a and 43bencircling a rubber sleeve 44 carried upon the tube 10. The clamp parts43:; and 43b are tightened upon the sleeve 44 by nut and bolt means 45and 46 having bolts 47 and 48 connected at spaced points with the apron16 of the bracket 13. This completes the structural details comprisingthe means that suspended the burner bodily from a wall of the heater ina vibration dampened noise proof manner with quiet results underresilient but stabilized operational conditions during all ordinaryfunctions of the burner.

By including further refinements and improvements into the combustionair circulatory and supply system of the burner greater combustion airefiiciency is possible with quiet operational results due to theelimination of some of the air disturbing factors of the blower andassociated parts. As seen in Figs. 6 and 7, the fan housing 1 comprisesa vertical fan chamber 49 having the scroll chamber 5%) communicatingwith the outlet chamber 51 through which air is directed out of thesleeve opening 52 into the blast tube 4. The outlet chamber 51 includesan oifset pocket 53 closed by a detachable cover 54 which will permitremoval of the burner head 12, etc., if such parts require inspection orservicing.

The fan chamber 49 has a laterally connected air inlet chamber 55 whichis concentric with the axis of motor 2. Chamber 55 has circumferentialair inlet openings 56 and a suitably perforated metal band 57 isadjustably secured about the walls of chamber 55 by a clamp screw 58such as best seen in Fig. 15. Circumferential regulation of the band 57around the wall of chamber 55 and the attainment of a properly selectedinlet air volume at the inlet end of the fan housing will provide agiven volume of air for use and combustion at the burner head and oildischarge end of the blast tube 4.

The fan housing 1 and inlet chamber 55 are separated by an integrallycast dividing wall 59 including an air inlet opening 61 arrangedconcentrically with the axis of the motor 2. The opening 60 is definedby an annular flange 61 originating in the plane of the dividing wall 59and terminating within the fan housing substantially in the locationbest seen in Fig. 6. The motor 2 has a drive shaft 62 traversing the fanhousing 1 and the intake chamber 55 for driving connection with the fueloil pump 7 to deliver the fuel oil under pressure to the burner head 12.A squirrel cage fan 63 is secured to and driven by the shaft 62 and thefan is substantially the width of the housing 1 and of a diameter suchas to cause the outer ends of the fan blades 6 l to rotate about thedividing wall flange 61.

The cooperative arrangement of the fan 63 and the air dischargingflanged opening of the fan housing definitely prevents recirculation ofthe inlet air in the fan housing thus eliminating turbulence of air withconsequent noisy operation all accompanied by inefficiency inperformance and in combustion air delivery to the fuel burning point inthe oil burner. The integral construction of dividing wall 59 and theflange 61 of the opening 60 coact to strengthen the entire body of thefan housing and the adjacent manifold parts including the pumpsupporting section of the housing 1. Furthermore, the inlet air may beaccurately metered by the combination of the control of the inlet air atchamber 55 by the perforated band 57 together with the flange 61 formingan air funnel to axially spill the air directly into the fan bladecavity of the fan 63 for full and complete transmission of air directlyto the burner head 12 and to the flame propagation point of such oilburner. The area of chamber 55 considered transversely to shaft 62 isone and one-half times the area of opening 66 to the fan, and openings56 must provide a collective inlet area at least equal to the area ofchamber 55 so as not to starve the fan.

The solid cast noise free housing shown in Figs. 6 and 7 shows an oilburner wherein the motor 2 is capable of attachment to housing 1 aboutand over an opening which is large enough to limit the fan 63 from themotor side with the fan blades 64 encircling the flange 61 of opening69. In larger oil burners the motor mountings do not permit assembly ofthe fan arrangement as in the foregoing described structure.

Figs. 8 and 9 therefore illustrate a modified arrangement for airtransmission from the air inlet to the fan housing having the sameadvantageous air funnel features. The burner housing 66 has a motor boss67 arranged about the Opening 68 for the motor 69 with the motor shaft70 passing through opening 68 to support a squirrel cage fan 71. Thelatter is brought into the casing through an opening 72 having aperipheral ring 73 to receive the edge 74 of the detachable inlet casing'75. A removable annular shield 76 is interposed between ring 73 andedge 74 and tightly held in place by the bolts 77 that secure the casingto the adjacent wall of tthe casing 66. An adjustable and rotatablelouver cone 7% is mounted upon the apertured casing 75 and the latteralso carries a fuel oil pump 7'9 driven by shaft 70. Removal of bolts 77allows removal of casing 75 and shield 76 to remove the fan 71.

In this burner the shield 76 provides the baffle means to separate thefan housing and inlet chamber and it functions to spill combustion airaxially into the interior of the blade barrel of the fan to provide evenand efiicient air passage through the blower and into the carburetionzone of the oil burner.

The burner head 12 and its associated mechanisms are all bestillustrated in Figs. 10 to 15 inclusive. The head 12 comprises a cupstructure having a cast base 80 and a tubular sleeve 81 having itsattached end seated in an annular base recess 82 with a plurality ofscrews 83 positioned radially through suitable sleeve openings forthreaded connection with base bosses 84. Lock nuts 85 engage the surfaceof sleeve 81 and lock the screws 83 in place as shown in Fig. 14.

Base 80 also has radially positioned lugs 86 to engage the interior ofthe blast tube 4 to position the head 12 centrally within the tube asbest shown in Figs. 18, 13 and 15, thus providing an annular air spacebetween the head 12 and tube 4 through which the air for combustion isdirected by the blower system comprising the inlet unit 55 and 57,opening 69 and flange 61, fan 63 and housing 1, and the connected blasttube 4.

Base 80 also has a boss 87 on .the outer face thereof with the bosshaving a configuration to accommodate three axially disposed bores 88,89 and 90. Bore 8S loosely receives and supports the head end of the oildelivery tube 9 centrally of the base 80 and of the sleeve 81. A setscrew 91 fixes the relative positions of the tube 9 and head 12 andholds the latter in a predetermined longitudinal position within thelast tube 4.

Electrodes 92 and 93, carrying the ignition wires 94 and 95, are looselysupported in the bores 89 and respectively. Suitable set screws 96 and97 engage the electrodes to position each longitudinally relatively tothe base 80 and to position each electrode against rotation within itsrespective bore to thus bring the ignition wires 94 and into operativerelation.

The oil line 9 is connected with and supports the oil delivery nozzle 98having a small diameter central opening 99 at its head end through whichoil is discharged by the pump in a finely atomized mist 100 as bestshown in Fig. 13. As shown in Fig. 15, the oil line 9 is arranged toincline upwardly from its oil receiving end at the coupling 10 to thehead end for the purpose of preventing after drip from the nozzle 98thereby eliminating the cause of sooting and the stench whichaccompanies such conditions. With an upslope in the oil line 9 anyentrapped air in the line will find its way out of the line and nozzlewithout carrying fuel oil with it through the nozzle. This arrangementtherefore provides means for automatically purging the oil line andnozzle in a gun type pressure burner to eliminate the heretoforeobjectionable after drip in an oil burner. Obviously, during operationthis arrangement carries on its intended task in the same fashion as anyother type of burner.

The base 80 of the head 12 includes a plurality of boss configurationsaccommodating openings 101 best seen in Figs. 10 and 14. These openings101 are bores having their axes angularly disposed with respect to thegeneral plane of the base 80 and also angularly arranged with respect tothe axial center line of the head to produce a composite whirl of airwithin sleeve $31 that moves toward the open end of sleeve 81 past theelectrode ignition wires 94 and 95 and past the oil blast nozzle 98. Theair that enters the head through the openings 101 is bypassed fromwithin the blast tube 4 containing air under pressure as supplied fromthe fan 63 through the housing 1 into the blast tube 4.

The purpose of the air inlets 101 at the rear of the head 12 is toprovide a means to prevent the formation of a vacuum within the head asa result of the velocity of the combustion air that sweeps over the headand over the front end thereof. The stolen air passing through inlets101 provides a means to assist in stretching out the are from the sparkat the ends of the ignition wires of the electrodes at a point adjacentthe discharge zone of the nozzle 98. This bypassed air also contributesto support combustion of the burning oil when ejected from nozzle 98during operation of the burner.

With this head structure the efiiciency of the burner is increased bythe fact that the oil flame is only directed forwardly out of the headand blast tube and into and across the combustion chamber of the heater.No vacuum detractions exist in the head. And these features whencombined with the'type of air cone 102 as herein used introduce burningefiiciencies and performance that have not been attained in comparableold type burners.

The air cone 102 is secured Within the discharge end of the tube 4 byone or more set screws 103, see Fig. 1. This cone 102 as bestillustrated in Figs. 10 to 13 comprises a peripheral sleeve 104terminating in a conical apron 105 disposed radially inwardly from thesleeve 104 and reentrant from the rear thereof which is the headreceiving end of the sleeve. A plurality of vanes 106 line the rear orair receiving face of the apron 105 and terminate rearwardly of theapron as prongs 107 having their end walls 108 circumferentiallycoincident with the outer circumferential surface of the sleeve 104 forflush contact within tube 4.

The vanes 106 are narrow at the outer cone periphery and widen out atthe fringe of the cone discharge opening 169 to produce a plurality ofair channels 110 on the surface of the apron 105 which then becomerestricted at 111 adjacent the air outlet opening 109 in the cone 102.As shown in Fig. 11, the vanes 106 are also located angularly withrespect to true radial planes of the cone to position the air channels110 in locations for discharging air that strikes apron 105 inindividually concentrated streams along the directions of the arrows 112in Fig. 11. Arrows 112 show the air stream paths as seen when looking atthe face of the air cone in Fig. 11, but the same air streams aredirected into the oil mist ball in paths indicated by arrows 113 in Fig.13.

The blower air from fan 63 passes through the blast tube 4 as shown bythe arrows in Fig. 13 and strikes the apron to divide into the channelswhich, due to their restricted discharge ends 111, discharge the blowerair in straight but nonspinning independently definable streams of highvelocity air through such restrictions and in a direction to drive thiscombustion air toward the center of the oil mist ball that is formingahead of nozzle 98 to provide intimate intermingling of air and oil forpromoting complete burning of the fuel. The oil discharged underpressure from the nozzle 98 expands into the oil mist ball 100 and indoing so penetrates and intercepts the plurality of individual forcedair streams guided by the shape of the cone toward the central zone ofthe oil mist ball. This action functions to stabilize the flow of oilmist and combustion air and contributes to the production of a clear hotflame of a predetermined size, shape and character, and with asubstantially constant B. t. u. output for the arranged setting of theburner. The cone 102 thus provides the means to drive the combustion airthrough the oil mist to support combustion of the mist principally bymeans of air within the oil mist ball.

Since the cone 102 has the apron 105 leading from its full externaldiameter, the vanes 106 pick up, deflect and guide the blast tube airfrom the full diameter of the tube and including some of the air comingout of the sleeve 81 of the head 12, all in a direction to inject airinside the oil mist ball for internal flame propagation. Thisarrangement prevents turbulation within the blast tube except in themanner described; while the air entering the head through openings 101produces spinning air in said head to prevent fouling with carbondeposits and to secure perfect air-oil mixture.

Referring again to Figs. 10 to 13, it should be noted that the vanes 106are all notched at 114 to provide a series of landings 115 circularlypositioned to receive and/or support the open end of the sleeve 81 ofthe head 12 in concentric relation with respect to the cone 102. Whenthe head 12 is in the full forward position with sleeve 81 bottomed inthe notches 114, the sleeve 81 is disposed at a given minimum distancefrom the surface of the cone apron 105 creating a valvular means toregulate air flowing through the passageways 116 as seen in Figs. 10 and13. This provides a set up with a given fuel capacity consumption. Bythe loosening the oil line screw 91 and by drawing the head rearwardlyin the blast tube 4 to a position indicated in dot and dash lines at 117(Fig. 13) to move the sleeve 81 relative to the apron 105, another setup is obtained which provides an increased fuel capacity consumptionwith a greater B. t. u. output to the heater 6 by reason of the controlof the air flow and air pressure at the cone by the movable head.

As a means for supporting or further guiding the front end of the head12 under the adjustable arrangement described, certain of the vanes 106are provided with extensions 118 to increase the lengths of the lands115 of the cone notches 114.

In installations requiring larger heat output from burners and acorrespondingly larger size of blast tube such as 4, the same head maybe used to supply the fuel oil. In such constructions the same type ofcone may be used with a larger central opening and without notches 114and the head 12 may be centered in the tube by backing out the screws 83until a three point positional support is affected in the larger tube.ead 12 may then still be adjusted along the oil line 9 for movementtoward or away from the cone and cone opening to regulate the air supplyand pressure for the conditions of use.

In the past the practice has been to use an oversupply of air which iswasteful and leads to fluttering and pulsation in the burners. An excessof cold air which is driven around the oil mist exerts considerablechilling effect between the flame and the heating surfaces. Theseundesirable conditions have been eliminated in the oil burner of thepresent design and construction. With the burner of this invention it ispossible to regulate the air flow and/ or pressure of the combustion airfrom the blower system, and with the cone used in conjunction with thehead described, the air is forcibly directed in streams into the oilmist ball to promote combustion from within the flame propagation zonewithout chilling the flame and the heating surfaces.

This action requires air control and the delivery of air from areservoir source supplying the correct amount of static pressure, such asource being the blast tube. By the head being movable on the oil lineand in relation to the cone, a metering arrangement is established atthe outlet point of the blast tube to control, at this point, the volumeof air and the air pressure. By the same token that the outlet airshould be controlled in this burner, it is also a function of the burnerto supply only a given amount of required air for potential butreleasable storage in the blast tube for sustaining combustion as neededand this can be done by air control to the fan at the intake end by themovable perforated band 57 upon the apertured inlet housing 55.

Since the burner may be set up to deliver a certain flame of a givensize and shape to fit the size of combustion chamber 5 of a heater 6 forobvious and added economy, and since this burner lends itself toempirical conditions for consistency of performance and operation, theprovision of a given static pressure condition within the blast tube 4prepares the oil burner for use to deliver a fixed B. t. u. output withless fuel consumption than has been possible with burners of comparablecapacities.

A test hole 119 normally closed with a threaded plug 120 has beenprovided in the blast tube 4 as shown in Figs. 5 and 15 for the purposeof having a means for the attachment of a manometer or other instrumentto determine the static air pressure within the blast tube, and for thepurpose of guiding adjustments in the air flow system of the oil burnerto obtain the set up that has the optimum efficiency and performancemade possible by the construction and design of the present oil burner.

Attention is directed to one other feature which resides in theproduction of a hollow flame by the present burner as made possible bythe head and cone combination herein disclosed and described relating tothe driving of air into the central zone of the oil mist. Hollow flameshave a greater outside surface and are more radiant to thus transfermore of the radiant energy to a heat absorbing surface thus effecting afurther saving in fuel costs.

To produce this hollow flame by the cone and head structure underpredetermined and uniform static air pressure, the means such as theblower or air supply system and the details of construction thereofbecome essentially important. The fan housing herein used is made toconform with the best known standards of construction of blower wheelhousings and includes such refinements that prevent recirculation of airwithin the housing which interferes with controlled air delivery.

In burners of the past construction the air was driven around the oilmist ball so that little attention was given to precision fan housingdesign. The sole aim was to supply sufficient air to support combustionplus enough excess air to prevent such' oil burners from producing asmoky flame. Uniform static air pressure was not a reqirement nor was itconsidered as essential to the operation of oil burners.

The burner of this invention illustrates a "complete change in theoperation of oil burners and incorporates all the essential mechanismswhich when combined produce a burner having all the salient featuresdisclosed and described which all contribute to economical and low costoperation. The burner is clean and precise in performance and requireslittle attention.

The details of construction of the air cone and its design contributeconsiderably to the operation of the burner. The restricted terminalends 111 of the channels 110 are made narrower than the widths of theterminal ends of the vanes 106, while the collective discharge areas ofthe channels are at least equal to the air discharge area of the blasttube. Thus full air flow is obtained in divided and concentrated streamsof air under a static pressure plenum of air as maintained in the blasttube at all times.

The sleeve 104 of the air cone 102 has been designed to perform severalfunctions contributing to the efiiciency and performance of the cone. Asseen in Figs. l0, l2 and 13, the sleeve 104 acts to stabilize andpartially confine discharged air and oil mist to more effectivelycommingle these fluids at this point, and if desired, the sleeve may belengthened or thickened to meet certain conditions of operation. Sleeve104 also provides an annular protection to safeguard the venturi portionof the cone as defined by the apron 105, and to prevent damage to thecone by the heat of the combustion chamber 5, counteracting unduedistortion and helping to dissipate heat from the body of the cone 102to the air tube 4.

As seen in Fig. 11, it should be noted that the air streams from 180degree positioned valleys are directed as near to the oil mist center aspossible, but offset with respect to each other to avoid interferencebetween opposite air streams across the cone.

The preferred construction of burner herein disclosed and describedillustrates one general construction adapted to the principles set forthand capable of functioning in the capacity stipulated. Changes in theexact construction and in the precise combination of associatedmechanisms are contemplated without departing from the fundamentalconcept of this invention. Such modification shall, however, be governedby the breadth and scope of the language defining the invention in thefollowing appended claims.

What I claim is:

l. A combustion unit for an oil burner comprising an air delivery tube,a head in said tube of smaller size than the tube to permit air to passaround the head and over the front end of the latter, an oil nozzlecarried by said head and adapted to form an oil mist ball in front ofthe head, and an air deflecting cone carried by said tube in advance ofthe head and nozzle comprising an annular apron sloped to conicallydirect the tube air into the oil mist ball ahead of said nozzle, saidapron having a plurality of vanes disposed about the surface thereof andpositioned to divide said tube air into a plurality of independent airstreams that are deflected by said apron into the aforesaid oil mistball to support combustion of the oil from within said mist zone, andsaid vanes each being tapered with their narrow ends at the tubeperiphery and their wider ends adjacent the air opening through saidannular apron whereby said vanes together with the surface of the apronprovide divisional air concentrating channels on said cone, said conechannels being narrower at their discharge ends than the widths of thevane ends at that point and to reduce the independent air streams insize but to increase their velocities for concentrated air jetpenetration of the oil mist ball.

2. A combustion mechanism for oil burners comprising an air deliverytube, a cup shaped head in said tube of reduced diameter to permit airflow about said head and over the open end of the head, an oil deliverynozzle in said head to emitvoil mist spray, and an air cone in said tubedisposed adjacent and overlapping a part of the open end of said head,said air cone having deflecting surfaces arranged thereon to divert thetube air into said oil spray for combustible commingling, and notchedmeans on said cone to receive the open end of said head in apredetermined minimum proximity with respect to the head overlappingportion of the air deflecting surfaces of the cone, and means toadjustably move said head relatively to said cone surfaces to regulatethe capacity of air discharged from said tube and between said cone andhead.

3. A combustion mechanism for oil burners comprising an air deliverytube, a fixed oil line in said tube terminating in an oil spraydischarge nozzle, an airflow regulating shield slidably carried on saidoil line, said shield providing regulatory tube air throttling means tocause a given volume of tube air to discharge annularly over said shieldtoward the nozzle end thereof, and an air cone disposed within said tubeand annularly in front of the nozzle end of said shield, said conehaving surfaces arranged to deflect the tube air stream into the oilspray zone at the nozzle, said deflecting cone surfaces includingnotched portions to accommodate the front end of said shield formovement toward or away from the air deflecting surfaces of said cone,and releasable means for adjustably locking the shield in a givenposition with respect to said oil line to fix the relation of the shieldwith respect to the air deflecting cone, certain portions of saidnotches comprising limit means to establish the maximum approach of saidshield toward said air cone for minimum airflow regulation.

4. A combustion mechanism for oil burners comprising an air deliverytube, a cup shaped head in said tube of reduced diameter to permit airflow about said head and over the open end of the head, an oil deliverynozzle in said head to emit oil mist spray, and an air cone in said tubedisposed adjacent the open end of said head, said air cone havingspirally positioned deflecting vanes arranged thereon to divert the tubeair into said oil spray for combustible commingling, said deflectingvanes of said cone including notched portions to center and accommodatethe open end of said head for a predetermined approach toward the airdeflecting surfaces of the cone, and means to adjustably move said headrelatively to said cone surfaces to regulate the air dischargerestriction of said tube, said head further including air bleed openingsin the closed end thereof to bypass tube air into the cup shaped head toscavenge the interior of said head and the zone surrounding said oildelivery nozzle.

5. An air cone for use in the blast tube of an oil burner and forcoaction with the oil feed means thereof comprising a sleeve to fit saidtube and having a continuous frusto-conical surface encircling theinterior of said tube, said frusto-conical surface of said sleeve havinga plurality of vanes arranged upon said surface to provide air deliverychannels between said vanes, and said vanes and channels being arrangedat their air delivery terminal ends with the vanes of greater width thanthe widths of said intermediate channels.

6. In an oil burner, an air delivery tube, and an air cone for said tubearranged to direct tube air into the oil spray discharged from the oilfeed means of the burner, said air cone comprising a frusto-conicalannular apron to divert tube air radially inwardly of the tube andconvergingly in the direction of the tube axis, a plurality of vanes onsaid apron to provide air flow channels therebetween, each of said vanesbeing spirally positioned upon the apron in respect to a transverseplane of the tube whereby said vanes are disposed at given angularpositions with respect to radial planes of the tube axis and to providespirally positioned channels therebetween, said vanes each havingenlarged widths atthe air discharge edge of said annular apron to narrowsaid channels at their discharge ends, said widths of the vanes beinggreater than that of the intervening channels.

7. An air deflecting cone for a blast tube of an oil burner comprising acontinuous deflecting apron surrounding a given diameter air supplyopening in said cone, and a plurality of vanes carried upon said apronto define air channels therebetween, said vanes each being relativelynarrow at the outer peripheral part of said apron to broaden the airreceiving portions of the channels at this location, and said vanesbeing relatively wider at the radially inner portion of said apron torestrict the width of the air channels at the air discharge edge of saidapron and to thereby increase the intensity of the air streamsdischarged from said cone.

8. In an 'oil burner, a blast tube, an endwise adjustable head in saidtube, an air'cone having an air deflecting surface thereon fixedlycarried within the tube in termediate the lengths of said vanes, andnotches formed.

in the surfaces of said cone vanes to provide clearance for thereception of said air metering edge portion of said head, said vanenotches having their bottoms located at a predetermined minimum distancefrom the References Cited in the file of this patent UNITED STATESPATENTS 1,495,731 Gerdes May 27, 1924 1,733,499 Klemm Oct. 29, 19291,755,090 Ainscow Apr. 15, 1930 1,777,141 Howden Sept. 30, 19301,783,405 Celander Dec. 2, 1930 2,156,121 Macrae Apr. 25, 1939 2,163,915Reif et a1 June 27, 1939 2,181,527 Vollner Nov. 28, 1939 2,215,272OBrien Sept. 17, 1940 2,248,395 Taper et al. July 8, 1941 2,287,595Beckett June 23, 1942 2,298,745 Klockau Oct. 13, 1942 2,316,224 DEliaApr. 13, 1943 2,325,893 Vollner Aug. 3, 1943 2,347,594 DeLin Apr. 25,1944 2,411,048 Logan Nov. 12, 1946 2,500,787 Lelgemann Mar. 14, 19502,603,280 Bernhard July 15, 1952

